The present invention relates to a fabric presser foot device for a sewing machine, wherein a presser foot movable in a vertical plane is mounted on a lower end of a presser bar.
Generally, a sewing machine is used to sew two superposed fabrics or leathers to be stitched together with a needle taking up a thread. This type of the machine is well known, for example, by Japanese Patent Publication (KOKOKU) No. 41080/1983 wherein a needle bar is arranged in parallel with a fabric presser bar in such a manner that the needle bar is moved upward and downward by synchronizing with a rotation of a main shaft of the machine and the fabric presser bar is movable on the needle bar. Disposed is a coil spring between a frame of the machine and the top of the fabric presser bar so as to press a presser foot formed on a lower end of the fabric presser bar against the fabrics or leathers to be sewn. In this case, when the needle is moved downward toward its dropping position, the coil spring is compressed and the biasing force of this compressed coil spring is exerted upon the fabrics or leathers to be sewn via the fabric presser foot which is moved downward for pressure contact with the fabric on a needle plate.
It is noted in a prior art that the fabric presser foot is forced to be dropped by the biasing force of the coil spring until it comes into collision with the fabric on the needle plate while the moving needle is stuck into the fabric. This collision is repeated at a high frequency so that undesired noise emits.
To eliminate such the noise Japanese Patent Publication (KOKOKU) No. 38239/1981 and Utility Model Publication (KOKOKU) No. 8855/1985 propose a fabric presser foot device as shown in FIGS. 7 and 8, wherein a main shaft 100 of a sewing machine is connected through a link 101 with a presser bar 102 having a fabric presser foot 103 at its lower end. A rotation of the main shaft 100 allows the presser bar 102 to be moved upward and downward so that a stroke of the fabric presser foot 103 with respect to a needle plate 105 is predetermined to reduce the noise.
However, a problem normally arises when the fabric of a hard material is sewn, because a weight of the presser bar 102 having the fabric presser foot 103 and a biasing force of a spring 104 are directly transmitted to the needle plate 105 through the fabric and the noise is not reduced to a comfortable level or magnitude.